Marine outboard electrical generator and assembly method

ABSTRACT

A outboard marine electrical generator unit capable of installation on the transom of a marine vessel which provides an electrical generating unit for small and medium sized marine vessels. The invention thus provides an A/C and D/C electrical power source capable of providing electrical power for appliances, air conditioning units and other electrical loads, even while the primary propulsion system is off and the vessel is docked or at anchor. The electrical generator includes: (1) a housing, including upper and lower portions, generally having the external appearance of an outboard motor; (2) an internal combustion engine; (3) a permanent magnet electrical alternator, including a rotor and stator, and a cooling fan, mechanically connected to the engine crankshaft; (4) a carburetor assembly, including feedback control responsive to electrical load; (5) an inverter module, including pulse-width-modulation (“PWM”) voltage regulation system and D/C-A/C inverter frequency regulation system; (6) an exhaust system terminating at the lower housing portion in a typically submerged location; (7) a fuel storage and delivery system, including either an internal and/or external fuel tank and a fuel pump; and (8) a transom mounting mechanism, preferably including a tilt feature.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of Provisional U.S. PatentApplication Serial No. 60/165,478, filed Nov. 15, 1999, titled MARINEOUTBOARD ELECTRICAL GENERATOR AND ASSEMBLY METHOD.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT

[0002] N/A.

BACKGROUND OF THE INVENTION

[0003] 1. Field of the Invention

[0004] The present invention relates to marine electrical generators,and more particularly to an electrical generator adapted forinstallation on the transom of a marine vessel. Electrical power isgenerated by an internal combustion engine, including a submergedexhaust port for discharging combustion gases below water, and apermanent magnet alternator. The electrical generator provides areliable and cost effective source of A/C and D/C electrical power foruse aboard marine vessels.

[0005] 2. Description of the Related Art

[0006] Marine vessels require power for many purposes. For example, asubstantial amount of power is typically required for propulsion (i.e.power to drive the propeller). In addition, power is also required foronboard electrical service (i.e. lighting, communication and navigationelectronics, etc.). As the power demands for propulsion and onboardelectrical service vary widely, large vessels are often equipped withtwo separate power generation systems—one for propulsion and one forelectrical power. Small and medium size vessels, however, are oftenforced to rely on the limited supply of electrical power available fromthe engine that drives the primary propulsion system, such as theelectrical power produced by an outboard motor. In situations where theprimary means of propulsion is an outboard motor, the availability ofelectrical power is severely limited. As a result, small and medium sizevessels are often forced to rely on an auxiliary portable generator unitas a source of electrical power. The use of portable generator units,however, presents a number of significant disadvantages including highcost, the presence of hot exhaust gases, excessive noise, difficultinstallations due to a lack of space, and the inability of transommounting. Thus, the background art reveals a number of auxiliary powergeneration devices provided for use with outboard motors.

[0007] For example, U.S. Pat. No. 2,879,738, issued Mar. 31, 1959(Culbertson), discloses a combined outboard motor and generating plant.The Culbertson reference discloses a generator mechanism comprising arotating armature type device used to simultaneously propel a boat whilegenerating electricity. U.S. Pat. No. 4,010,377, issued Mar. 1, 1977(McKenzie), discloses a combined generator and boat propulsion systemwherein the generator drive shaft is coupled to the propulsion unitdrive shaft via a centrifugal clutch (16). McKenzie discloses an openframework device further provides a second/auxiliary drive sprocket(70). U.S. Pat. No. 4,695,261, issued Sep. 22, 1987 (Broughton),discloses a marine propulsion device having a voltage generator mountedthereto. Broughton discloses a configuration wherein the voltagegenerator is located in the recess in the underside of the flywheel andan annular power takeoff pulley (132) mounted on the flywheel. Broughtonrelies on a pulse generator (61) for the conventional capacitordischarge ignition circuit in addition to the power generator (63). U.S.Pat. No. 5,011,442, issued Apr. 30, 1991 (Polcz et al.), discloses anauxiliary power generation device for use in an outboard motor. Polcz etal. teach adapting an outboard motor by mounting an alternator coaxiallywith the flywheel to provide 1000 watts of D/C. power. The Polczreference further discloses an available inverter for providing A/Cpower in addition to the D/C power supply.

[0008] The electrical generating devices of the background art, however,fail to provide a fully functional light weight outboard generatorcapable of being mounted on the transom and able to produce high qualityand clean A/C and/or D/C electric power responsive to varying electricalloads while maintaining a substantially sound proof construction and asubmerged exhaust.

BRIEF SUMMARY OF THE INVENTION

[0009] The present invention provides an outboard marine electricalgenerator unit capable of installation on the transom of a marinevessel. The outboard generator according to the present inventionprovides an electrical generating unit for small and medium sized marinevessels (specifically power and sail boats in the 20-40 foot range) thatare otherwise not equipped with an auxiliary electrical generator and/ordo not have space available for the installation of a conventionalonboard marine generator. The invention thus provides an A/C and D/Celectrical power source capable of providing electrical power forappliances, air conditioning units and other electrical loads, evenwhile the primary propulsion system is off and the vessel is docked orat anchor.

[0010] An outboard marine electrical generator according to the presentinvention includes the following primary components: (1) a outboardmotor-type housing, including upper and lower portions, generally havingthe external appearance of an outboard motor but for the absence of apropeller; (2) an internal combustion engine; (3) a permanent magnetelectrical generating assembly, including a rotor, a stator, and acooling fan, mechanically connected to the engine crankshaft; (4) acarburetor assembly, including feedback control responsive to electricalload; (5) an inverter module, including pulse-width-modulation (“PWM”)voltage regulation system and D/C-A/C inverter frequency regulationsystem; (6) an exhaust system terminating at the lower housing portionin a typically submerged location; (7) a fuel storage and deliverysystem, including either an internal and/or external fuel tank and afuel pump; and (8) a transom mounting mechanism, preferably including atilt feature.

[0011] The above-referenced device provides a transom mountable marineoutboard generator powered by a 4-stroke, single-cylinder gasolineengine that is capable of producing 1,000 VA at the following electricalratings: 120 VAC/7.5 A/60 Hz and/or 12 VDC/8.0 A. The power supplied issufficient to power, among other things, a 5,000 Btu marine airconditioning system for providing comfort cooling. The outboardgenerator weighs approximately 34 lbs, and is capable of operating forapproximately 6 hours on a single gallon of gasoline. The outboardgenerator provides for the submerged discharge of exhaust therebyminimizing noise levels and reducing the likelihood that noxious exhaustfumes will accumulate in occupied parts of the vessel. Outboardgenerators according to the present invention may be fabricated withgreater electrical generating capacities using larger horsepowerengines.

[0012] It is an object of the present invention to provide a transommounted electrical generator for marine vessels.

[0013] Still another object of the present invention is to provide atransom mounted marine electrical generator capable of producing bothA/C and D/C electrical power for providing small and medium sized marinevessels with sufficient and cost effective power for running a varietyof electrically operated devices including cabin air conditioning units,lights, computers and other electronic devices.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0014]FIG. 1 is a side elevational view of a marine outboard generatoraccording to the present invention;

[0015]FIG. 2 is a partially exploded side elevational view of awater-cooled marine outboard generator according to the presentinvention, illustrating cooling water intake and submerged exhaust flow;

[0016]FIG. 3 is a partial exploded perspective view showing the rotor,stator, and cooling fan components in relation to the engine/crank shaftas found within the engine cowling;

[0017]FIG. 4 is an exploded partial front perspective view detailing thefront control panel assembly for the marine outboard generator;

[0018]FIG. 5 is an electrical wiring schematic for a marine outboardgenerator according to the present invention;

[0019]FIG. 6 is an electrical schematic showing the throttle controlfeed back circuit.

DETAILED DESCRIPTION OF THE INVENTION

[0020]FIGS. 1 through 6 depict a preferred embodiment of a marineoutboard generator according to the present invention. The presentinvention comprises an outboard marine A/C and D/C electrical generatorfor transom mounting on a marine vessel. The outboard generator providesan electrical generating unit for small to medium sized boats(specifically power and sail boats in the 20-40 foot range) that areotherwise not equipped with sufficient electrical generating capacity,or which are not configured and/or do not have sufficient spaceavailable for the installation of a conventional onboard marinegenerator. The invention thus provides an A/C and D/C electrical powersource for powering appliances, air conditioning units and otherelectrical loads while the vessel cruises and/or is at anchor.

[0021] In a preferred embodiment, an outboard marine electricalgenerator according to the present invention includes the followingprimary components: (1) a housing, including upper and lower portions,preferably resembling a propellerless outboard motor; (2) an internalcombustion gasoline engine; (3) an electrical generating assembly,including a stator, and a rotor and a cooling fan connected to theengine crankshaft; (4) a carburetor assembly, including a feedbackcontrolled throttle control motor responsive to electrical load; (5) aninverter module, including pulse-width-modulation (“PWM”) voltageregulation system and D/C-A/C inverter frequency regulation system; (6)an exhaust system terminating at a submerged outlet; (7) a fuel deliverysystem, including an external fuel tank and a fuel pump; and (8) atiltable transom mounting mechanism.

[0022] By way of a preferred example there is disclosed a marineoutboard generator based in part on a 2.0 HP air-cooled marine outboardengine. An outboard generator based on such an outboard engine resultsin a fully functional transom mounted electrical generator suitable foruse on marine vessels for providing power for onboard electricalcomponents and cabin air conditioning units. An outboard generatoraccording to the present invention is compact, lightweight, extremelyquiet and economical and provides a source of both A/C and D/Celectrical power. In alternate embodiments, larger engines, e.g. 5-25h.p. or larger, either air cooled or water cooled may be used to achievehigher electrical generating capacities.

[0023] As best depicted in FIG. 1, a marine outboard generator accordingto the present invention, generally referenced as 10, includes a housinghaving an upper portion 12 and a lower portion 14. The housing ispreferably generally shaped in the form of an outboard engine. It shouldbe noted however, that the external shape of the outboard generator neednot identically resemble an outboard engine, provided, however, that thegenerator include a housing having an upper portion for containing theinternal combustion engine and generator components, and a lower portionfor providing a submerged exhaust capability. Housing upper portion 12includes an upper portion base 12A and a removable cover 12B. Inaddition, the generator includes a transom mounting mechanism 16 forattaching the generator to the transom of a marine vessel as shown inFIG. 2. Transom mounting mechanism 16 preferably comprises a quickconnect clamp for secure attachment to the transom and may furtherinclude a tilt of pivot capability to allow the generator to be tiltedwhen not in use such that the lower portion 14 rises above the waterline.

[0024] As depicted in FIG. 2, housing upper portion 12 provides aprotective enclosure for an internal combustion engine 20 mountedtherein. In a preferred embodiment, capable of producing a maximumoutput of approximately 1,000 VA, the internal combustion engine maycomprise a 4-stroke single cylinder engine having a displacement ofapproximately 3.5 cubic inches (57 cm³). Such an engine is preferablyair-cooled, but may be liquid-cooled (e.g. water-cooled, oil cooledetc.). Engine 20 has a suitable compression ratio, such as 8.0:1. Theengine is preferably disposed in a horizontal configuration wherein theengine cylinder is generally horizontally disposed, however, avertically disposed engine configuration remains within the scope of thepresent invention. The engine includes a piston that drives a crankshaft22. Crankshaft 22 is generally vertically disposed within the housing.Engine 20 further includes an exhaust system, generally referenced as24, having a first end 24A connected to the engine cylinder block and asecond end 24B terminating in the housing lower portion for dischargingexhaust at a submerged location.

[0025] An electrical generator assembly, generally referenced as 30, isconnected to the top portion of the internal combustion engine. Asignificant aspect of the present invention includes the use of apermanent magnet alternator. The electrical generator assembly includes:a stator 32, fixed relative to engine 20; a rotor 34, having a permanentmagnet 34A attached to a peripheral edge thereof, is fixedly connectedto the engine crank shaft for rotation therewith; and a cooling fan 36,also connected to the engine crank shaft to provide forced air inductioncooling. The use of a permanent magnet alternator provides a number ofadvantages in performance and safety. For example, the use of apermanent magnet alternator eliminates the need for a heavy counterbalancing flywheel. Instead, the permanent magnet alternator relies onmagnetic forces that are harnessed and synchronized with the enginecycle to counter balance periodic vibrational forces generated bymovement of the piston. The elimination of the flywheel substantiallyreduces the cost and weight of an outboard generator fabricatedaccording to the present invention as compared to a similar constructionusing brush-type alternators and/or any other flywheel typeconfiguration. FIG. 5 shows an electrical wiring schematic for anoutboard generator according to the present invention. As best seen inFIG. 3 an ignition pulse generator, referenced as 39, is mountedadjacent to the rotor/stator assembly and electrically connected to theengine's spark plug. The ignition pulse generator 39 is mounted in closeproximity to the peripheral edge of rotor 34 which includes a signalgenerating permanent magnet, referenced as 34A. Ignition pulse generator39 functions to send a properly timed spark generating electrical pulseto the spark plug thereby causing a spark within the engine's cylinder.

[0026] As best seen in FIG. 3, a recoil starter assembly 38, isconnected to the engine crank shaft. The starter assembly includes astarter pulley 38 and a starter rope (not shown), which cooperate tofunction as a recoil starter. The outboard generator further includes afuel tank having a fuel supply line fluidly connected to a twelve-voltDC (12 VDC) fuel pump located within the housing. In a preferredembodiment, a fuel tank 70 and 12 VDC pump 72 comprise a fuel storageand delivery system for the internal combustion engine. The fuel tankand pump may be mounted externally from the generator and onboard themarine vessel and function to deliver fuel to the internal combustionengine during operational periods. In an alternate embodiment (notshown) the fuel tank and pump may be incorporated into the housing forthe internal combustion engine and/or fixedly attached externally to thehousing.

[0027] The outboard generator further includes an inverter unit 40 andcontrol panel 42. The inverter unit includes a pulse width modulationvoltage regulation system and frequency regulation is accomplished byDC-AC conversion. The inverter unit is electrically connected to atleast one AC output receptacle and at least one DC output receptacle,which receptacles may be incorporated on control panel 42 along withother control devices and gauges. As best seen in FIG. 4, the controlpanel is preferably incorporated into the housing upper portion 12 so asto face the stem of the marine vessel when the generator is mounted tothe transom as shown in FIG. 2.

[0028] Engine 20 further includes a carburetor 50 and throttle controlmotor 52. Throttle control motor 52 is electrically connected toelectrical load sensing circuitry and is responsive to the electricalload placed on the generator via a feedback control circuit asschematically illustrated in FIG. 6. Accordingly, the throttlecontinuously matches engine speed to the electrical load on thegenerator. For example, as the feedback control circuit senses that theelectrical load placed on the generator is increasing a signal is sentto the throttle control motor to increase the throttle/fuel flow.Conversely, as the feedback control circuit senses that the electricalload placed on the generator is decreasing a signal is sent to thethrottle control motor to decrease the throttle/fuel flow. FIG. 6provides an electrical schematic of the throttle control load sensingfeed back circuitry.

[0029] As best seen in FIG. 3, a cover assembly, generally referenced as60, is disposed within the upper housing 12 and encloses all of theprimary engine and generator components. The cover assembly, may includefirst and second components referenced as 60A and 60B respectively, andfunctions to protect the enclosed engine and generator components fromsalt water exposure while facilitating ventilation. In an air cooledembodiment, heat generated by the internal combustion engine andgenerator assembly is removed through convection cooling and isprimarily achieved through forced air ventilation as fan 36, driven byengine 20, functions to draw air from the surrounding environmentthrough housing 12 and cover 60 and around the engine prior to beingdischarged through housing ventilation ports.

[0030] The electrical generator is configured for use with a marinevessel by: (1) mounting the generator to the transom using transommounting mechanism 16 as shown in FIG. 2; (2) installing the fuel tank,pump and fuel line; (3) electrically connecting AC and/or DC powerconsuming devices to the generator; and (4) starting the generator usingthe recoil starter mechanism. It should be noted that the electricalgenerator may be electrically connected directly to the vessel's powersupply system, such as by electrically connecting an electrical outputline from the generator to an electrical input on the vessel, such asthe shore power input. In the alternative, individual power consumingdevices, such as a marine cabin air conditioning unit, may be directlyconnected to the generator.

[0031] The internal combustion engine causes rotation of rotor 34relative to stator 32 thereby generating a DC voltage potential that maybe converted to an AC voltage potential by inverter 40. In an alternateembodiment, however, the alternator may directly produce AC electricalcurrent which may then be routed through a PWM inverter assembly, whichPWM inverter assembly may be remotely located from the transom mountedunit (e.g. onboard the marine vessel), to produce current at a desiredvoltage and frequency (e.g. 120 VAC/60 Hz). As illustrated in FIG. 6,engine RPM is controlled by a feedback control system to matchelectrical load. Exhaust from the internal combustion engine isdischarged below the waterline through exhaust outlet 24B. Dischargingthe exhaust external to the vessel and below the waterline provides asafe and quiet means of handling the exhaust. As earlier disclosed theinternal combustion engine may be either air-cooled or water-cooled. Inthe water cooled embodiment depicted in FIG. 2, water is drawn into thelower portion of the housing through a water intake 26 and routedthrough suitable engine cooling conduit whereafter the cooling water maybe mixed with exhaust from the engine and discharged.

[0032] Attached hereto as a two page Appendix (A-1, and A-2) arespecifications, dimensions and operating characteristics for a preferredembodiment of a marine outboard electrical generator according to thepresent invention. It should be noted, however, that otherspecifications, dimensions and operating characteristics arecontemplated and within the scope of the present invention.

[0033] The present invention has been shown and described herein in whatis considered to be the most practical and preferred embodiments. It isrecognized, however, that departures may be made therefrom within thescope of the invention and that obvious structural and/or functionalmodifications will occur to a person skilled in the art.

What is claimed is:
 1. An electrical generator for installation on a marine vessel, said electrical generator comprising: an internal combustion engine having a projecting crankshaft, an air intake for providing combustion air to said engine, and an exhaust system including an exhaust outlet for discharging engine exhaust; means for mounting said internal combustion engine to the transom of a marine vessel such that said air intake is in fluid communication with the ambient atmosphere and said exhaust outlet is disposed below the vessel's waterline; a permanent magnet alternator mechanically connected to said crankshaft for producing electrical current; electrical output means for supplying an electrical current from said electrical generator to external power consuming devices.
 2. An electrical generator according to claim 1, further including an inverter electrically connected to said permanent magnet alternator, said inverter capable of producing alternating current at a desired voltage and frequency.
 3. An electrical generator according to claim 1, wherein said internal combustion engine is air-cooled.
 4. An electrical generator according to claim 1, wherein said internal combustion engine is liquid cooled.
 5. An electrical generator according to claim 1, further including means for regulating fuel flow to said internal combustion engine in response to electrical demand.
 6. An electrical generator according to claim 5, wherein said means for regulating fuel flow includes feedback carburetor control for adjusting engine speed in response to electrical load.
 7. An electrical generator according to claim 6, wherein said feedback carburetor control includes an electric throttle control motor connected to a carburetor and feedback control means for sensing the electrical load placed on the electrical generator, said feedback control means controlling said electric throttle control motor throttle fuel flow.
 8. An electrical generator according to claim 1, wherein said internal combustion engine further includes means for generating a properly timed electrical pulse electrically connected to a spark plug connected to said internal combustion engine.
 9. An electrical generator according to claim 8, wherein said means for generating a properly timed electrical pulse comprises an ignition pulse generator.
 10. An electrical generator according to claim 9, wherein said ignition pulse generator is mounted in close proximity to the periphery of said permanent magnet alternator.
 11. An electrical generator for generating electrical power output for use by electrical devices on a marine vessel, said electrical generator comprising: a housing, said housing having an upper portion and an elongate lower portion depending downward from said upper portion, said housing further including means for removably mounting said housing to a marine vessel; an internal combustion engine contained within said housing, said internal combustion engine including a projecting crankshaft, a carburetor fluidly connected to a fuel pump, said fuel pump fluidly connected to a fuel tank, said internal combustion engine further including an air intake and an exhaust port; means for generating electrical power connected to said internal combustion engine, said means for generating electrical power including a permanent magnet alternator, said permanent magnet alternator including a rotor and a stator, said rotor fixedly connected to said crankshaft for rotation relative to said stator; an inverter electrically connected to said permanent magnet alternator, said inverter capable of converting direct electrical current to alternating electrical current; power outlet means electrically connected to said inverter for providing means for transmitting electrical power generated by said means for generating electrical power to electrical power consuming devices onboard the marine vessel.
 12. An electrical generator according to claim 11, further including means for regulating fuel flow to said internal combustion engine in response to electrical demand.
 13. An electrical generator according to claim 12, wherein said means for regulating fuel flow includes feedback carburetor control for adjusting engine speed in response to electrical load.
 14. An electrical generator according to claim 13, wherein said feedback carburetor control includes an electric throttle control motor connected to a carburetor and feedback control means for sensing the electrical load placed on the electrical generator, said feedback control means controlling said electric throttle control motor throttle fuel flow.
 15. An electrical generator according to claim 11, wherein said housing has an appearance similar to the appearance of an outboard motor housing.
 16. An electrical generator according to claim 11, wherein said means for mounting said housing to a marine vessel includes a pivotal connection whereby said housing may be pivotally moved from a first position wherein said housing lower portion terminates below the surface of the water to a second position wherein said housing lower portion terminates above the surface of the water.
 17. An electrical generator according to claim 16, wherein said housing lower portion includes an exhaust conduit having a first end in fluid communication with said outlet port and a second end terminating below the surface of the water when said housing is in said first position.
 18. An outboard electrical generator for generating electrical power for use by electrical power consuming devices on a marine vessel, said marine vessel having a hull with a transom, said hull having a waterline disposed along the surface of the body of water supporting the marine vessel when the vessel is loaded as designed, said electrical generator comprising: a housing, said housing having an upper portion and an elongate lower portion depending downward from said upper portion, said housing further including bracket means for removably mounting said housing to the transom of a marine vessel; an internal combustion engine contained within said housing, said internal combustion engine including a projecting crankshaft and a carburetor fluidly connected to a fuel pump, said fuel pump fluidly connected to a fuel tank, said internal combustion engine further including an air intake and an exhaust port; a permanent magnet alternator connected to said internal combustion engine, said permanent magnet alternator including a rotor and a stator, said rotor fixedly connected to said crankshaft for rotation relative to said stator; an inverter electrically connected to said permanent magnet alternator, said inverter capable of converting direct electrical current to alternating electrical current; a control panel mounted to said housing upper portion and electrically connected to said permanent magnet alternator and said inverter, said control panel including power outlet means for providing means for transmitting electrical power generated by said permanent magnet alternator to electrical power consuming devices onboard the marine vessel; feedback control circuitry means for sensing the electrical load on said generator, said feedback control circuitry electrically connected to a throttle control motor, said throttle control motor connected to said carburetor for increasing and decreasing air and fuel flow to said internal combustion engine in response to electrical load placed on said generator.
 19. An outboard electrical generator according to claim 18, wherein said internal combustion engine further includes a recoil starter.
 20. An outboard electrical generator according to claim 18, wherein said internal combustion engine further includes an ignition pulse generator electrically connected to a spark plug.
 21. An outboard electrical generator according to claim 18, wherein said power outlet means includes at least one AC electrical outlet.
 22. An outboard electrical generator according to claim 18, further including means for electrically connecting said power outlet means to the electrical power supply system of a marine vessel. 